Chapter 5- Populations Flashcards
What is a “trophic cascade”?
The impact of the removal of a top consumer
What will happen to prey if the predator is removed?
The prey population will increase
What will happen to the producers if the predators are removed?
They will decrease because of the over population of prey.
What are some of the population characteristics???
range (geographic distribution), density (# per area), growth rate (rate of increase or decrease), and age structure
What is “Exponential Growth”?
growth pattern in which the individuals in a population reproduce at a constant rate.
What is “Logistic Growth”?
growth pattern in which a population’s growth rate slows or stops following a period of exponential growth.
What is “Carrying Capacity”?
largest number of individuals of a population that a given environment can support.
What is “Limiting Factor”?
factor that causes the growth of a population to decrease
What is a “Density- Dependant Limiting Factors”?
limiting factor that depends on population size.
What happens to a population’s growth after it reaches the carrying capacity?
The population growth decreases because the population’s resources start to decline and competition starts.
What is a “Predator- Prey Relationship”?
mechanism of population control in which a population is regulated by predation.
What is “Demography”?
scientific study of human populations.
What are “Demographic Transitions”?
change in a population from high birth and death rates to low birth and death rates.
What is the “Age-Structure Diagram”?
graph of the numbers of males and females within different age groups of a population.
Explain how population can possibly exceed its carrying capacity?
A population can exceed its carrying capacity by having ideal conditions
What happens when birth-rate = death rate?
The population will remain constant, creating a plateau, if the birth and death rates are equal.
What are the 3 determining factors of population growth rate???
Birth rate, death rate, and migration (emigration and immigration)
What occurs when individuals in a population reproduce at a constant rate, multiplying the number of reproducing individuals.
Exponential population growth
Under ideal conditions and with unlimited resources, a population will grow __________.(J-shaped graph)
exponentially
As resources become less available, population growth slows or stops after a period of exponential growth forming which type of graph.
Logistic growth (S-shaped graph)
What can humans do to decrease an animal population
Relocate animals and introduce predators
What is a limiting nutrient
a single nutrient that is either scarce or cycles very slowly, limiting the growth of organisms in an ecosystem.
ex: Nitrogen and Phosphorus
What is competition???
Fighting over important resources such as food, water, shelter, space, sunshine, and mates.
How could a predator increase the population of another species in its habitat?
The predator can increase the population of another species in its habitat by eliminating it’s predator.
What is predation???
The predators (hunters) when catching prey (hunted) and the relationship between the populations of the predators and the prey.
Why would a contagious virus be considered a density dependent limiting factor?
A contagious virus is density-dependent because if the person with the virus stays alone, the virus will not spread. This is because viruses depend on a host.
What are renewable resources???
resources that can be regenerated quickly and is replaceable.
ex: trees, hydro-energy, solar energy
What shape line does exponential growth create?
J
What shape line does logistic growth create?
S
What type of line is linear growth?
Horizontal
LOOK OVER GRAPH SHEET
:)
What are non-renewable resources?
A resource that cannot be replenished by natural processes.
ex: fossil fuels like coal, oil, and natural gas
What is the MOST likely outcome if a population grows larger than the carrying capacity?
Increase in death rate will occur because of low resources.
What is gestation?
The amount of time from conception to birth.
What is ecology?
The scientific study of interactions between organisms and their environments.
What is a species?
A group of organisms that breed and produce fertile offspring.
What is the “Independent Factor”?
the factor or condition that is changed or manipulated (factor being tested) `
What is the “Dependent Factor”?
the factor being measured as a result of the independent variable.
What is the difference between immigration and emigration?
Immigration- organisms into a population
Emigration- organisms leaving a population
When does logistic growth occur?
When a population reaches the carrying capacity and encounters limiting factors.
List the levels of organisation.
1) organism 2) population 3) community 4)ecosystem
5) biome 6) biosphere
What are the two main commodities?
sunlight and matter (nutrients)
What is the “control”?
the test set up except the factor or condition being tested.
Arrows show what in a food web?
The flow of energy
What is a chemoautotroph?
Bacteria at the bottom of the ocean, where sunlight doesn’t reach, that oxidizes inorganic compounds, forming the bottom of the food chain.
What is the “constant”?
all the factors that are kept the same throughout the test groups.
What is the effect of a limited resource on a population?
Competition would occur to get that resource and the population would decrease.
What is a food chain?
the series transfers through consumption
What is a food web?
a network of food chains
What is a trophic level?
a step in the food chain
What determines the length of a food chain?
energy
What are pyramids?
Pyramids are diagrams that show the relative amounts of energy or matter at each trophic level of food chains and food webs.
What does the energy pyramid depict?
the amount of energy at each trophic level and 10% is passed to each level and the rest is lost by heat
How can you account for the fact that the human population has grown more rapidly during the past 500 years than throughout its previous history?
In the past 500 years, humans have been living in ideal conditions. Medicine has gotten stronger, causing a decrease in disease. Also technology has gotten stronger, being able to identify more harmful agents inside the body.
What is the biomass pyramid?
shows the amount of potential food available in each trophic level
What is biomass?
the amount of tissue within a trophic level
What does the numbers pyramid show?
shows the number of individuals at each trophic level
